PROJECT SUMMARY/ABSTRACT The aim of the Interdisciplinary Training in Cancer Research Program is to train young scientists to design and conduct research on significant problems in cancer by combining information and approaches from different scientific disciplines, including basic cellular and molecular biology, epidemiology, clinical trials and studies, and behavioral-social sciences. The rationale behind this program is to produce researchers who can excel in the increasingly complex environments and interdisciplinary approaches required for future cancer research. The program is a highly competitive and demanding training program. For 2-3 years, trainees work closely with two mentors who provide distinct, complementary areas of expertise; for example, by studying basic molecular and cellular mechanisms of neoplasia in combination with epidemiological analyses of related risk factors; or by participating in clinical research studies while studying behavioral or environmental factors that influence therapeutic outcomes. Our trainee projects transcend the traditional boundaries separating the molecular and cellular, clinical, epidemiologic and social cancer sciences. As a result, the program differs fundamentally in focus, goals and training plans from other pre- and postdoctoral training programs in the Seattle biomedical research community. The program supports two separate types of interdisciplinary trainees. The first are PhD candidates and postdoctoral fellows who work within two separate research groups to study a common problem in cancer using unique, and yet complementary research disciplines. The second are graduate students who are enrolled in a dual-degree program that allows PhD students in the Molecular and Cellular Biology (MCB) graduate program to earn a concurrent MS in Epidemiology. Trainees in either track are supported by this training grant as part of a broad initiative in Seattle to create a scientific culture in which interdisciplinary cancer research and training is encouraged and fostered. Three separate institutions ? University of Washington, Fred Hutchinson Cancer Research Center, and Seattle Children's Research Institute ? serve as primary research sites for trainees and their mentors. Faculty mentors have primary appointments at one of the three participating institutions, and the majority have additional cross- institutional affiliate appointments in the Fred Hutch/UW Cancer Consortium. We have created an environment across institutions where pre- and postdoctoral fellows can become conversant in the goals, assumptions, logic, methods, and vocabulary of multiple research disciplines.